In April 2004, William A. Tozier auctioned his services as a co-author on eBay. The winner of the auction would receive Tozier's help writing a paper. Tozier has an Erdős number of 4, so one of the benefits of winning the auction was an Erdős number of at most 5. Tozier said that the auction began as a joke but as he was contacted by people who "expressed a frustrated desire to do research," the auction became serious. Jose Burillo, an associate professor of mathematics at the Polytechnic University of Catalonia (Spain), was offended by the auction and offered an inflated bid of over US$1,000 to end the bidding. Erica Klarreich writes that Burillo was declared the original winner of the auction but because his was a protest bid, Tozier wound up contacting the next-highest bidder. That bidder backed out of the auction because of a lack of time. As of publication of the articles, no winner had been declared. Tozier said that any payment he receives would be used to start an online community for scientific collaboration.